diff --git a/pkgs/development/compilers/opensmalltalk-vm/default.nix b/pkgs/development/compilers/opensmalltalk-vm/default.nix
index 82481a8e17eb..3ee6953ba4de 100644
--- a/pkgs/development/compilers/opensmalltalk-vm/default.nix
+++ b/pkgs/development/compilers/opensmalltalk-vm/default.nix
@@ -180,7 +180,7 @@ let
 
   platform = stdenv.targetPlatform.system;
 in
-  vmsByPlatform.${platform} or throw (
+  vmsByPlatform.${platform} or (throw (
     "Unsupported platform ${platform}: only the following platforms are supported: " +
     builtins.toString (builtins.attrNames vmsByPlatform)
-  )
+  ))